[pacman-dev] [PATCH v2 2/3] makepkg: use the `declare` builtin when backing up variables to eval

[Eli Schwartz]

This re-applies commit 9e52a36794552b77ecf26f7f34b226d096978f1e with
fixes after reverting it in 10ca4f48311370cdd580f66096d5e94858fde467 for
the maintenance release.

The split package metadata backup/restore was initially refactored to
use declare, which actually declares variables in a local scope when in
a function. This did not play nicely with debug packages, which unset
most metadata variables, thereby reverting to the global scope rather
than resulting in unset metadata.

This could be fixed by explicitly marking the variables as global, or,
alternatively, by refactoring everything to use local function
variables. However, the latter simply moves the issue to other areas
(what happens if a user-defined package function uses unset instead of
foo=() for the same effect).

Now that the minimum version of bash has been raised, it is safe to once
more apply (a working version of) this enhancement.

Signed-off-by: Eli Schwartz <eschwartz at archlinux.org>
---

v2: patchset now targets pacman 6.x and is rebased onto
https://patchwork.archlinux.org/patch/631/

 scripts/makepkg.sh.in | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
index d35dd62d..5f351ef5 100644
--- a/scripts/makepkg.sh.in
+++ b/scripts/makepkg.sh.in
@@ -1125,34 +1125,26 @@ check_build_status() {
 backup_package_variables() {
 	local var
 	for var in ${splitpkg_overrides[@]}; do
-		local indirect="${var}_backup"
-		eval "${indirect}=(\"\${$var[@]}\")"
-	done
-}
-
-restore_package_variables() {
-	local var
-	for var in ${splitpkg_overrides[@]}; do
-		local indirect="${var}_backup"
-		if [[ -n ${!indirect} ]]; then
-			eval "${var}=(\"\${$indirect[@]}\")"
+		if [[ ${!var} ]]; then
+			printf '%s\n' "declare -g $var"
+			declare -p $var
 		else
-			unset ${var}
+			printf '%s\n'  "unset $var"
 		fi
 	done
 }
 
 run_split_packaging() {
 	local pkgname_backup=("${pkgname[@]}")
+	local restore_package_variables="$(backup_package_variables)"
 	for pkgname in ${pkgname_backup[@]}; do
 		pkgdir="$pkgdirbase/$pkgname"
 		mkdir "$pkgdir"
-		backup_package_variables
 		run_package $pkgname
 		tidy_install
 		lint_package || exit $E_PACKAGE_FAILED
 		create_package
-		restore_package_variables
+		eval "$restore_package_variables"
 	done
 	pkgname=("${pkgname_backup[@]}")
 	create_debug_package
-- 
2.17.1